Impact-induced bonding process of copper at low velocity and room temperature

Abstract

The impact-induced bonding can be foundation of fast solid-state additive manufacturing. The mechanisms behind impact-induced bonding have not been widely acknowledged due to complexity caused by too transient process and extreme loading conditions. We report a novel impact-induced bonding process of copper flakes. This bonding process possesses attractive features of longer duration, macroscopic characteristic length and low ambient temperature (typically at room temperature). Meanwhile, finite element simulation based on actual grain configurations and crystal plasticity reveals that the bonding strength can reach the strength of bulk material. Three types of bonding modes are observed and corresponding mechanisms are extracted. It is found that the embedding between microstructures and the recrystallization of grains are significant factors of impact-induced bonding. Both microstructure characterization and simulation with material point method support recrystallization but not melting.

Keywords

• Impact-induced bonding
• Low velocity
• Room temperature
• Recrystallization